Toner is a
A powder is a dry, bulk solid composed of many very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms ''powder'' and '' granular'' are sometimes used to disti ...
mixture used in laser printer
s and photocopier
s to form the printed text and images on paper, in general through a toner cartridge
. Mostly granulated plastic, early mixtures only added
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes up o ...
powder and iron oxide
, however, mixtures have since been developed containing
Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene.
belongs to the group of polyolefins and i ...
, fumed silica
, and various minerals for triboelectrification
. Toner using plant-derived plastic also exists as an alternative to
Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crude ...
plastic. Toner particles are melted by the heat of the fuser
, and are thus bonded to the paper.
In earlier photocopiers, this low-cost carbon toner was poured by the user from a bottle into a reservoir in the machine. Later copiers, and laser printers from the first 1984 Hewlett-Packard LaserJet, feed directly from a sealed toner cartridge.
Laser toner cartridges for use in color copiers and printers come in sets of cyan, magenta, yellow and black (
The CMYK color model (also known as process color, or four color) is a subtractive color model, based on the CMY color model, used in color printing, and is also used to describe the printing process itself. The abbreviation ''CMYK'' refers ...
), allowing a very large
In color reproduction, including computer graphics and photography, the gamut, or color gamut , is a certain ''complete subset'' of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circ ...
to be generated by mixing.
Composition, size and manufacture
The specific polymer used varies by manufacturer but can be a
Styrene () is an organic compound with the chemical formula C6H5CH=CH2. This derivative of benzene is a colorless oily liquid, although aged samples can appear yellowish. The compound evaporates easily and has a sweet smell, although high conc ... acrylate copolymer
polyester resin Polyester resins are synthetic resins formed by the reaction of dibasic organic acids and polyhydric alcohols. Maleic anhydride is a commonly used raw material with diacid functionality in unsaturated polyester resins. Unsaturated polyester re ...
, a styrene butadiene copolymer, or a few other special polymers. Toner formulations vary from manufacturer to manufacturer and even from machine to machine. Typically formulation, granule size and
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depend ...
vary the most.
Originally, the particle size of toner averaged 14–16
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer ( American spelling), also commonly known as a micron, is a unit of length in the International System of Un ...
s or greater. Theoretically, for the perfect reproduction of dots and print features at 600 dpi, a particle size of about 5 μm is required and, at 1200 dpi, about 3 μm is required. Further reductions in particle size producing further improvements in resolution are being developed through the application of new technologies such as Emulsion-Aggregation
. Toner manufacturers maintain a
Quality control (QC) is a process by which entities review the quality of all factors involved in production. ISO 9000 defines quality control as "a part of quality management focused on fulfilling quality requirements".
This approach places ...
particle size distribution
The particle-size distribution (PSD) of a powder, or granular material, or particles dispersed in fluid, is a list of values or a mathematical function that defines the relative amount, typically by mass, of particles present according to size. Sig ...
in order to produce a powder suitable for use in their printers.
Toner has traditionally been made by compounding the ingredients and creating a slab which was broken or pelletized, then turned into a fine powder with a controlled particle size range by air jet milling
. This process results in toner granules with varying sizes and aspherical shapes. To get a finer print, some companies are using a chemical process to grow toner particles from molecular reagents. This results in more uniform size and shapes of toner particles. The smaller, uniform shapes permit more accurate colour reproduction and more efficient toner use.
Toner can be washed off
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other animal coverings, such as the arthropod exoskeleton, have different d ...
Clothing (also known as clothes, apparel, and attire) are items worn on the body. Typically, clothing is made of fabrics or textiles, but over time it has included garments made from animal skin and other thin sheets of materials and natural ...
s with cold water. Hot or warm water softens the toner, causing it to bond in place. Toner fused to skin eventually wears off, or can be partially removed using an abrasive hand cleaner. Toner fused to clothing usually cannot be removed. Unfused toner is easily cleaned from most water-washable clothing. Because toner is a wax or plastic powder with a low melting temperature it must be kept cold while cleaning.
Toner particles have
Electrostatics is a branch of physics that studies electric charges at rest ( static electricity).
Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for am ...
properties by design and can develop static-electric charges when they rub against other particles, objects, or the interiors of transport systems and vacuum cleaner hoses. Because of this and the small particle size, toner should not be vacuumed with a conventional home
A vacuum cleaner, also known simply as a vacuum or a hoover, is a device that causes suction in order to remove dirt from floors, upholstery, draperies, and other surfaces. It is generally electrically driven.
The dirt is collected by either a ...
. Static discharge from charged toner particles theoretically may ignite dust in the vacuum cleaner bag or create a small explosion if sufficient toner is airborne. Toner particles are so fine that they are poorly filtered by household vacuum cleaner filter bags and can blow through the vacuum motor into the room. They can also cause overheating by clogging the motor filter and
A short circuit (sometimes abbreviated to short or s/c) is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circu ...
by their electric conductivity (carbon, iron) when they melt inside the motor.
If toner spills into the laser printer, a special type of vacuum cleaner with an electrically conductive hose and a high efficiency ( HEPA
) filter may be needed for effective cleaning. These are called
Electrostatic discharge (ESD) is a sudden and momentary flow of electric current between two electrically charged objects caused by contact, an electrical short or dielectric breakdown. A buildup of static electricity can be caused by tribochar ...
-safe (ESD-safe) or toner vacuums. Similar HEPA-filter equipped vacuums should be used for clean-up of larger toner spills.
Muhle et al. (1991) reported that the responses to chronically inhaled copying toner, a plastic dust pigmented with carbon black, titanium dioxide and silica, were also similar qualitatively to titanium dioxide and diesel exhaust
, one of the components of toner, is classified as "possibly carcinogenic" ( Group 2B
) by the
IARC IARC may refer to:
* International Aerial Robotics Competition
* International Age Rating Coalition
The International Age Rating Coalition (IARC) is an initiative aimed at streamlining acquisition of content ratings for video games, from authori ...
As a fine powder, toner can remain suspended in the air for some period, and is considered to have health effect
s comparable to inert
Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in ho ...
. It can be an irritant to people with
The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies gr ...
conditions such as
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, coug ...
. Following studies on
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were amo ...
in the 1970s that raised concerns about health effects resulting from
Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4 H4 NH. It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., ''N''-meth ...
, a contaminant created during manufacture of the carbon black
used in black toner, manufacturing processes were changed to eliminate pyrrole from the finished product.
Research by the
Queensland University of Technology
Queensland University of Technology (QUT) is a public research university located in the urban coastal city of Brisbane, Queensland, Australia. QUT is located on two campuses in the Brisbane area viz. Gardens Point and Kelvin Grove. The uni ...
has indicated that some laser printers emit submicrometer particles which have been associated in other environmental studies with
Respiratory diseases, or lung diseases, are pathological conditions affecting the organs and tissues that make gas exchange difficult in air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, ...
A study at the
University of Rostock
The University of Rostock (german: link=no, Universität Rostock) is a public university located in Rostock, Mecklenburg-Vorpommern, Germany. Founded in 1419, it is the third-oldest university in Germany. It is the oldest university in continen ...
has found that the microscopic particles in toner are carcinogenic, similar to asbestos. Several technicians who had been working with printers and copiers on a daily basis were observed for several years. They showed increased lung problems. This confirms previous research published in 2006.
Research at Harvard University has shown that, during printing, metal-oxide nanoparticles (defined as 100 nanometres and smaller, hence 0.1 micrometres and smaller) are released into the air from toner-based laser printers and multifunction devices. These machines use toner particles that are on average 20 micrometres in overall diameter, but the surfaces of the toner particles themselves carry innumerable tiny metal-oxide nanoparticles. These ultra-small metal-oxide nanoparticles are highly bioactive and could cause harm to the lungs and also elsewhere in the body, given that particles 0.1 micrometres and smaller can cross biological membranes (including lung alveoli), thereby gaining access to all organs via blood circulation. This remains an area of active research, with many knowledge gaps.
The toner container can be a simple pack, for toner storage and transportation, or further, a consumable component of the printer.
The most common way to consume toner is with a toner cartridge
(or ''laser toner''),
as an office supply
of a laser printer
Several toner manufacturers offer toner in wholesale quantities. Typically, bulk loose toner is sold in barrels or 10 kg (22-pound) bags.
Toner is then used by a variety of industries in order to provide consumers with a finished laser toner cartridge.
Original Equipment manufacturers such as HP
Canon or Canons may refer to:
Arts and entertainment
* Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base
* Literary canon, an accepted body of works considered as high culture
** Western ca ...
as well as manufacturers of compatible toner cartridges use the toner in the process of manufacturing a brand new OEM cartridge.
Remanufacturers of toner cartridges use the bulk toner in the process of creating remanufactured toner cartridges. Other companies use the toner to provide a toner refill
Most toner cartridges are available to the average consumer through retail outlets or local remanufacturing operations. Remanufactured and refilled toner cartridges are generally offered at a lower cost than original toner cartridges, having been either wholly remanufactured and then refilled with toner (the more-optimal method) or just refilled with toner (the less-optimal method).
Recycling of pre-consumer waste toner is practiced by most manufacturers. Classifying toner to the desired size distribution produces off-size rejects, but these become valuable feedstocks for the compounding operation, and are recycled this way. Post-consumer waste
toner appears primarily in the cleaning operation of the photo-printing machine. In early printers, as much as 20 to 25% of feed toner would wind up in the cleaner sump and be discarded as waste. Improved printer efficiencies have reduced this waste stream to lower levels, although on average 13% of the toner in each cartridge is still wasted. Some printer designs have attempted to divert this waste toner back into the virgin toner reservoir for direct reuse in the printer; these attempts have met with mixed success as the composition of the toner will change by expending fusibles while retaining developer particles. Some consideration and fewer industry attempts have been made to reclaim waste toner by cleaning it and "remanufacturing" it.
Most toner goes to printed pages, a large fraction of which are ultimately recycled in paper recovery and recycling operations. Removal of toner from the pulp is not easy, and toner formulations to ease this step have been reported. Hydrolyzable, water-soluble, and caustic-soluble toner resins have been reported, but do not appear to enjoy widespread application. Most
The recycling of paper is the process by which waste paper is turned into new paper products. It has a number of important benefits: It saves waste paper from occupying homes of people and producing methane as it breaks down. Because paper fi ...
facilities mix toner with other waste material, such as inks and resins, into a sludge with no commercial use.
Toner-modified asphalt binder
Since toner consists of several copolymers and it is a carbon-based material, it can be used as a useful modifier for the asphalt industry. It has been shown that inclusion of left-over burnt toner enhances the rheological and mechanical properties of asphalt binder, significantly. Such an application can be placed as an environmentally friendly alternative to prevent soil contamination due to the landfilling of waste toner. Adding waste toner into asphalt binder and mixture decreases the binder's glass transition temperature and also, in the meantime increase the crystallization temperature as well.
[Notani, M. A., Moghadas Nejad, F., Khodaii, A., & Hajikarimi, P. (2018). Evaluating fatigue resistance of toner-modified asphalt binders using the linear amplitude sweep test. Road Materials and Pavement Design, 1-14.]
''Material Safety Data Sheets: HP LaserJet Print Cartridges''
The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware component ...
''Toner Particles – Monitoring Particle Size Distribution and Particle Shape''
from Malvern Instruments